Although Microsoft CEO Steve Ballmer has always exuded unwavering confidence in public interviews, behind closed doors he’s apparently being much more candid. The Verge reports that Microsoft held an in-house town hall event this week where Ballmer admitted to Microsoft employees that the company “built a few more” Surface RT tablets “than we could sell,” which might be an understatement given Microsoft’s recent $900 million charge that some analysts claim translates to as many as 6 million unsold Surfaces piled up in warehouses.

Ballmer also admitted that the company is “not selling as many Windows devices as we want to” and that it now plans to turn its focus to the back-to-school and holiday seasons to boost its sales figures. To that end, Microsoft has teamed with Best Buy to open in-store “Windows Stores” in more than 600 locations to raise awareness of Windows-based smartphones and tablets.

Finally, Ballmer told Microsoft employees that testing for a second-generation Surface RT was underway, although he didn’t give any details for how it would be different from the original or when it might launch.